Best NVA Amps for Quad ESL57 Speakers

[wackyraces]

Try with a Leak Stereo 20. I’ve never liked the Quad 2 Monos. In fact, I’ve yet to find a Quad amp that I liked.

OK I have a Quad 405 mk1 that I haven’t fired up yet so I don’t know if it’s likely to sound good or bad. But I thought I would give it a fighting chance by fronting it with an NVA P50sa I ordered recently (my first NVA - and my first Quad).

[Geoff.R.G]

Try with a Leak Stereo 20. I’ve never liked the Quad 2 Monos. In fact, I’ve yet to find a Quad amp that I liked.

OK I have a Quad 405 mk1 that I haven’t fired up yet so I don’t know if it’s likely to sound good or bad. But I thought I would give it a fighting chance by fronting it with an NVA P50sa I ordered recently (my first NVA - and my first Quad).

There is a note in the Quad 405 2 manual stating that Limiters must be fitted when driving Quad electrostatics prior to the ESL-63. Electrostatics prior to S/N 16800 need a minor modification before being used with a 405 2. I suspect the 405 1 manual contains something similar.

The limiters limit the output voltage to 20V.

You can find the user manual here HiFi Engine

[wackyraces]

Try with a Leak Stereo 20. I’ve never liked the Quad 2 Monos. In fact, I’ve yet to find a Quad amp that I liked.

OK I have a Quad 405 mk1 that I haven’t fired up yet so I don’t know if it’s likely to sound good or bad. But I thought I would give it a fighting chance by fronting it with an NVA P50sa I ordered recently (my first NVA - and my first Quad).

There is a note in the Quad 405 2 manual stating that Limiters must be fitted when driving Quad electrostatics prior to the ESL-63. Electrostatics prior to S/N 16800 need a minor modification before being used with a 405 2. I suspect the 405 1 manual contains something similar.

The limiters limit the output voltage to 20V.

You can find the user manual here HiFi Engine

That's useful to know thanks. The previous owner never ran them with electrostatics so I think that limiter has been removed. I have a bag with bits and pieces in which include a limiter (or two?), a tape module (Quad replaced that with an MC module) and cables. I have the Quad 44 pre that belongs to it but that is one complicated looking beast - I like the simplicity (and hopefully better sounding) of the NVA P50sa.

[_D_S_J_R_]

Two ways to use 57's and my experiences are with a 1978 made pair and equivalent age 405...

Adding the limiters to the 405 circuit kills it stone dead if percussive music is to be enjoyed - in my opinion. String quartets is one thing, but well recorded rock and jazz at sensible '57 tolerant' levels is another..

Sometime in the 80's, Quad developed some limiters to be fitted to the speakers themselves and I fitted them to this particular pair, which I knew well. Doing this and removing the limiters in the amp improved the sound of rock and jazz-funk music I felt, the speakers sounding rather less constricted.

By eleven years old (1989), the 'sound' had gone off again and examination showed the 405 supply caps were leaking (little mounds of 'something' on top of both caps). The amp was converted into a 405-2 at the same time (it was affordable and worth it then). The 'clamp' board behind the speaker sockets was abandoned as it's on the mk2 boards anyway and the horrible speaker terminals were replaced with NVA-esque 4mm sockets. Even with a 44 preamp, the sound blossomed and became far more three-dimensional. Quad went through several mk1 layouts on the boards, but the mk2 was issue 7 and has stayed that way I gather up to date. The input op-amp is in the circuit in this design, so changing the ancient one to something a little better (OPA134) may offer an improvement, any more opening the bandwidth too much and risking instability (check the Dada site for full info).

Spurred by the above, a year or so later, the owner decided to update to a 66/606 pair, me buying the 405-2 and using it for a short while (better than an early Linn LK280 as long as the load wasn't silly low impedance). The 57's were used with the later pairing until my friend's passing several years ago and the whole system (Marantz CD80 and vinyl with Spacedeck/RB300/AT-F5 cartridge) sounded absolutely lovely in her small room, the 'beaming' not really an issue here as it sounded best just off axis...

I like the 405-2, but the two I had at different times, into different speakers and driven by different preamps, did have a slight subjective 'sting' for a few hours from cold, which only dissipated once the case got very warm to hot (half an hour when thrashed into ATC 20's ). Once this slight sting or sparkle disappeared and the sound was delightful as long as the speaker wasn't an awkward one for loading.

[Bencat57]

Just to clear up one statement made Quad ESL 57 are not active speakers as such they have no amplification fitted inside the speaker and in this should be viewed and treated as a passive speaker .

As electrostatic units they do need a connection to the mains this is in order to apply a voltage to the stators and ensure that the thin mylar panels are fully charged in order to be rigid and act as panels .

[Bencat57]

Okay due to another member here Inow have an NVA A20 power amp on its way . As I do not have any NVA speaker cable I will have to buy a set of L2 to just get me going and see how it sounds .

Will probably get it all wired up (provided the cables arrive in time) next Friday or Monday that I can give it a listen and see how it all sounds . If the 20 proves to be a good match I will then consider either a 70 or 80 monos which I would prefer . Realise that as i have bought second hand that I can not use the 20 for return or exchnage but I feel confident that I could sell it on and either get my money back or a small loss. Worth it just so I can get the chance to hear what NVA will do with the Quad 57's . I need a long time to listen to equipment in my room and system before i make my mind up about how they sound . I know some people can tell very quickly but I always need an extended listen just to make sure it is not just a different sound and long term not better.

[karatestu]

Hello Bencat,

How did it go with the NVA amp on the ESL 57's ? I am very interested in hearing a pair of Quad's having never heard an electrostatic speaker in my life.

Thanks, Stu

[valvesRus]

Hello Bencat,

How did it go with the NVA amp on the ESL 57's ? I am very interested in hearing a pair of Quad's having never heard an electrostatic speaker in my life.

Thanks, Stu

Get to hear a pair if you can Stu, preferably at home.

I had a pair for a while, they sounded best with my DIY 50W single ended Mosfet amp, A Nelson Pass design.

Sadly I passed the ESL57s on as they were a tad too big for my living room.

[karatestu]

How big are they ?

[karatestu]

I googled it. 88 x 79 x 27 cm. Not exactly small